From the National Geographic: On a 1441 metres high peak, the Buzludzha Monument was built by the Bulgarian communist regime to commemorate the events in 1891 when the socialists led by Dimitar Blagoev assembled secretly in the area to form an organised socialist movement. It was opened in 1981. No longer maintained by the Bulgarian government, it has fallen into disuse. Approaching and visiting the building in the middle of winter was a real adventure.